Windshield heater



Dec. 13, 1932. B. A. KNOWLES wINDsHIELD HEATER Filed Nov. 18. 1951 Patented Dee. 13, 1932A BERNARD A. KNOWLES, OF AZALIA, MICHIGA WINDSHIELD HEATER Application med November 18,1931. lseriaiifre. 575,694. f

This invention relates to windshields for automobiles, trolley cars, locomotives and thev like, and in particular to a heated wlndshield, `Y

for preventing the accumulation thereon of moisture in the form of ice, snow, mist, frost," etc., which might interfere with the clear vision of the driver. n

The object of the invention 1s the provision of a simple and comparatively rinexpensive '1 device of this character which will effectively operate to maintain a predetermined portion of a windshield Jfree from the accumulation of ice, snow, or sleet thereon and will also prevent moisture of condensation from collecting on the inner side of said portion, thus maintaining a clear vision through the windshield and rendering driving of vehicles safe in cold and stormy weather.

The invention is fully described in the ollowing specification, and while in its broader aspects, it is capable of embodiment in nue merous forms, one embodiment thereof is il# lustrated in the accompanying drawing, 1n which,-

Figure 1 is a rear or inner side elevation of a windshield equipped with my invention and with a portion broken away. Figs. 2

and 3 are enlarged sections, respectively, ony

thelines 2-2 and 3-3 in Fig. 1, and Fig. 4 is an enlarged cross-section of the heater element taken on the line 4-4 in Fig. 1.

Referring to the drawing, 1 designates a glass used for windshield purposes, whether on an automobile or otherwise, and mounted in a frame 2.

The portion of this glass through which it` is desired to maintain clear vision in cold or stormy weather is covered at its rear or innery side, in the present instance, with a transparent protecting member 3 preferably com prising a single pane of glass mounted in a frame 4, which cooperates with the glass 1 and its frame 2, or both, to space the glass members 1 and 3 in substantially parallel relation to form a closed chamber 5 therebetween. A packingf may be provided between the marginal edge portion of the member 3 and the glass 1 and its frame 2 both to y prevent rattling and to more effectively close the chamber 5 against the loss of heat provided thereinfas hereinafter described.` c

The protecting member 3 is shown, in the present instance, as'detachably hinged at its top to the frame 2, as at 7, and as beingreleas` 55 ably secured at its lower edge' portion yto saidframe by a thumb screw 8 which extends through the frame 4 and threads into the frame 2.

In order to effect a sufficient heating of the glass ly to melt ice and sleet which may have accumulated thereon, or toprevent such accumulation, and to have 'the portion of the `glass so affected coextensive with the chamber 5, or at least with the portion of the glass i desired to be kept clear for vision'purposes, it is not only necessary to apply sufiicientheat to the chamber 5 for that purpose, but also to maintain ak circulation of such heat within the chamber. y 7

This is'accomplishedfby providing an arm 9 within the chamber for movements therein in parallel relation to the glass and adapted to cover a considerable areaof the glass in such movement, and to provide such arm withv a heat generating or distributing means. The arm 9 may be attached to a motor 10 of any suitable type, for imparting the requisite movements thereto within the chamber, the same, for instance, as used in connection with Windshield wipers, the arm, in the present instance, being adapted to have swinging movements in said chamber.

The heating feature of the arm constitutes, in the present instance, an electrical resistance heater 1l disposed in, or carried by, the arm substantially throughout its length and having suitable connection at its inner end with a storage battery or other convenient rsource of electrical supply. f The swinging of the heater arm agitates and setsup a circulation of the heated air in the chamber 5 and causes a substantially uniform heating of the glass in the outer, or exposed, side of the chamber and prevents moisture of condensation from occurring within the chamber and accumulating on the glass and also suiificiently heats the glass 1 to prevent the accumulation of ice, snow or the like on itsy outer surface.

The customary wiper element 12 is mounted on the outer side of the windshield glass 1, to clean the same, and its carrying arm 13 is suspended from, and operated b a motor 14, as well understood in the art. t is apparent that, if desired, a common motor may be employed for actuating the Wiper member 12 and heater arm 9. The manner of actuating the heater arm is not important to the invention and such manner need not, therefore, be speciiically shown.

It is apparent that the member 3, 4, forming the inner side Wall of the chamber 5, together with the heater arm 9 andits `actuating means, may be built as a unit and be of a 15 character to enable it to be easily and quickvly attached to or removed from a windshield, thus enabling itto be vin connection with a windshield only during cold weather.

I wish it understood that my invention is "120 not limited to any specific construction, ar-

- rangement or form of the parts, as it is capab'le of numerous modiications and changes -without departing from the spirit of 'the claims.

'i125 `Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent is:

1. A Windshield having double transparent portions separated in the line of vision therej through to form an air space therebetween,

and means for supplying heat to said air space 'and movable in said space to agitate f and set up a circulation of air therein.

Q. A windshield having double transparent i portions separated in the line of vision there- V'through to form an air space therebetween and means for supplying heat to said air space, said means being automatically movable to change its position in said space.

"` 40 3. rl`he combination with a windshield 'of a substantially flat transparent member applied t0 one'side ofthe windshield and cooperating therewith to form a closed air space therebetween in the line of vision throughthe Windshield, and means within said space for heating the `air therein and automatically movable to shift itsposition in the space.

el. The combination with a windshield of an 'attachment therefor comprising a`transpar ent member at one side of the windshield cooperating therewith to form a closed air spacel therebetween in the line of vision through the windshield, and an electrical heater element disposed within said space to heat the air 'therein and movable to agitate the heated air. In Vtestimony whereof I have hereunto signed my name to this specification.

BERNARD A. KNOVLES. 

